First primitive beatdetection in place.

1 files changed, 70 insertions, 0 deletions

diff --git a/src/beatmapper.cc b/src/beatmapper.cc
new file mode 100644
index 0000000..6a7e35a
--- /dev/null
+++ b/src/beatmapper.cc
@@ -0,0 +1,70 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            beatmapper.cc
+ *
+ *  Fri Jul 25 11:17:42 CEST 2008
+ *  Copyright 2008 Bent Bisballe Nyeng
+ *  deva@aasimon.org
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#include "beatmapper.h"
+
+BeatMapper::BeatMapper(Instrument *instrument)
+{
+  this->instrument = instrument;
+  for(size_t i = 0; i < HISTORY_SIZE; i++) hist[i] = 0.0;
+  C = 1.3;
+  mindist = 2;
+  last = mindist;
+}
+
+
+Sample *BeatMapper::map(jack_nframes_t nframes)
+{
+  Sample *sample = NULL;
+  
+  jack_default_audio_sample_t *buffer;
+  buffer = (jack_default_audio_sample_t *)jack_port_get_buffer(instrument->port, nframes);
+  
+  float e = 0.0;
+  for(size_t i = 0; i < nframes; i++) {
+    e += buffer[i] * buffer[i];
+    //    buffer[i] = 0.0;
+  }
+
+  float E = 0.0;
+  for(size_t i = 0; i < HISTORY_SIZE; i++) E += hist[i] / (float)HISTORY_SIZE;
+
+  printf("last: %d, E: %f,  e: %f - threshold: %f\n", last, E, e, 1.3 * E);
+
+  // Shift history and save new value
+  for(size_t i = 0; i < HISTORY_SIZE - 1; i++) hist[i] = hist[i+1];
+  hist[HISTORY_SIZE - 1] = e;
+
+  if(e > C * E && last > mindist) {
+    Velocity *v = instrument->getVelocity(127);
+    if(v) sample = v->getSample();
+  }
+
+  last++;
+  if(sample) last = 0;
+
+  return sample;
+}